Add support for Golo language

![logo-golo](https://f.cloud.github.com/assets/1280212/310461/4ce51ab6-971d-11e2-86ec-7711a1202e20.png) — a lightweight dynamic language for the JVM.

`The world didn't need another JVM language. So we built yet another one. A simple one.`

I add the support of Golo files (with the `golo` lexer in `languages.yml` and some samples (see [old pull-request](https://github.com/github/linguist/pull/453)).

```golo
module hello.World

function main = |args| { 
  println("Hello World")
}
```

some links
- http://golo-lang.org/
- https://github.com/golo-lang
- https://github.com/TypeUnsafe
- https://gist.github.com/k33g/cdb6fc19ce1d1a5b6636
- https://gist.github.com/k33g/916270841da536db12b5
- https://gist.github.com/k33g/31733c66c510a4309979
- https://github.com/rlespinasse/ansi-string-augmentations.golo

What's our strategy for picking colors? A color from the golo logo might be more appropriate.

![](http://golo-lang.org/images/logo-golo.png)